September 12, 2013

Are ancient mtDNA sequences from Syria of Indian origin?

Honestly, I have all kind of doubts but that's what a new study claims on the basis of just a few hypervariable sequence markers:

Henry W. Witas, mtDNA from the Early Bronze Age to the Roman Period Suggests a Genetic Link between the Indian Subcontinent and Mesopotamian Cradle of Civilization. PLoS ONE 2013. Open accessLINK [doi:doi:10.1371/journal.pone.0073682]

The authors sequenced the HVS-I (and nothing else!) of the mtDNA of four individuals from Tell Ashara and Tell Ashaik sites of ancient Terqa and Kar-Assurnasirpal (Syria, Euphrates river). And then they proceded to establish a bit unlikely comparisons with East and South Asian M sublineages, of which only one is present today in the region.

The sequences are (supp table 3, all numbers +16,000 and counting from the CRS, i.e. H2a1 underived, GenBank: NC_012920):
  • TQ28F112: 223-234
  • MK13G117: 223-234-311
  • TQ28F256: 223-234-270
  • MK11G107: 223-266-289
The first two are attributed to M9, the third one to M61 (a quite rare haplogroup) and the last one to M4b (the only one to be found in West Asia nowadays, specifically in Arabia Peninsula).

Now what do the markers actually say? All are highly variable sites and independently can be found in many lineages, however most typically:
  • 223 describes R, hence counting from the CRS, it should mean L(xR).
  • 311 describes L3, hence counting from the CRS it should mean L(xL3).

So all four should be L(xR) and MK13G117 looks like L(xL3).

Exceptions for 311 (consistent with the sequence above): L3b1a3, M4'65'67, M10, M29'Q, M31a1, M56, M57 and M74. However M9 does not make it because to begin with it needs a transition at the 362 site. 

The authors got carried away by their own pre-conceptions and the marker 234, shared by three of the four sequences. However, while that marker is found in M9a, it also needs the 362 marker, which they both lack. So they are not M9 but something else. 

More plausible candidates could be, at least for TQ28F112, M30d/e or M49.

As for the rest, there are no modern sequences, at least via PhyloTree (but neither within the study's own comparisons), that are good correlates. All we can say with certainty is that they are L3(xR), except in the case of MK13G117, which can only be described as  L(xR). 

Maybe if they had tried sequencing the coding region, as in my understanding, they MUST (destroying or damaging valuable ancient bones to do this mediocre research is not anymore justified, if it ever was), they would have got useful and informative results. Now we just have again another frustrating set of nearly useless HVS-I sequences, which can only be ambiguous in the vast majority of cases.

Ah, by the way, there's no obvious correlation between these Metal Ages' sites and ancient Sumerians, of course. Even if the lineages are South Asian by origin or affinity, which is possible but by no means demonstrated, they would at most suggest a relation between the Mid-Upper Euphrates and that area. The region was under intermittent Sumerian, Amorite, Babylonian, Kassite and Assyrian control but mostly is a distinct country within the greater Mesopotamian area.

Notice that previous research (ref.) in the same area but from the Neolithic (PPNB) period has found (also HVS-I) large amounts of mtDNA K, some H and also some L3(xR).

[Note: edited because some ethnographic assumptions I made initially seem to be quite wrong].


Update (2015): the chronology actually corresponds with the Mitanni period. This suggests that whatever true Indian mtDNA was brought by Indo-Aryans coming directly from Pakistan or nearby areas (rather than from the steppe).

4 comments:

  1. The location of these two sites connect it with (Semitic) Assyrian or Amoritic origins, not Hurrian/Mitanni. The later group was centered in the northern rim of Mesopotamia, while these places are more to the south.

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    1. Assyrian affinity is not what I gather from the maps I have seen (now and always): the Assyrian core is limited to Assur, after all they are a Semitic frontier offshoot in an essentially non-Semitic area, and their homeland is anyhow located at the Tigris (within modern Iraq, Saladin province), not at the Euphrates and not within the borders of the Syrian state.

      Now regarding Amoritic, it's harder to discern indeed because this group was much more widespread and eventually controlled also much of Mesopotamia. Nearby Mari was ruled first by the people maybe related to Sumer, destroyed by the Akkadians but rebuilt, and later ruled by the Amorites, being finally destroyed by Babylon.

      As for Terqa, it was first ruled by Mari, then Babylonians (originally Chaldeans, akin to Amorites but later ruled by the Kassites too, non-Semitic), and only in the last period by the Assyrians. But, as in the case of Mari, I do not think that we can attribute their base population to either conqueror elite, although some Amorite relation is plausible (for example they worshiped the same fertility god, Dagon, venerated also in other Amorite cities of Syria and Lebanon).

      In any case, I thank you for raising these concerns because I now realize that the Hurrian attribution is probably not correct either and that the sites are not really in Western Kurdistan but in Arabic territory. I will correct that.

      Delete
  2. Back in 2005, I saw an online article about the discovery of an image (on a cylindrical seal, maybe?) from bronze age Mari, which was identified as being unmistakably similar to images of a temple in the Indus Valley. I recall the article also mentioned a bronze age trade road connecting Mari with the Indus. Mari was a major production facility for the bronze industry, so perhaps they were importing tin from South Asia, presuming their copper was coming from Cyprus?

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    1. That's an interesting piece of info, thanks.

      Delete

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